Campbell soup - sweet and sour soup

1. Skin chicken with sharp knife; cut into 2 inch long slices.
2. Sprinkle with salt.
3. Mixi cornstarch with 3 tablespoons water and soy sauce, combine with beef broth and water.
4. Bring to boil; stir often; add chicken, mushrooms and liquid, vinegar, and sugar.
5. Heat; simmer 5 minutes.
6. Serve with a slice of lemon in each bowl, a cruet of vinegar on the table.